Key operated telephone call transmitter



Feb. 12, 1946. RF. MALLlNA 2,394,926

KEY OPERATED TELEPHONE CALL TRANSMITTER I Filed Nov. 16, 1944 4 Sheets-Sheet 1 FIG-/ 42 A Kl0 INVENTOR R F MALL/NA Feb.'12, 1946. R. F. MALLINA KEY OPERATED TELEPHONE CALL TRANSMITTER Filed Nov. 16, 1944 4 Sheets-Sheet 2 //v VENTOR R'EMALL/NA 'A TZORNE! Feb. 12, 1946. R Q A 7' t 2,394,926.

KEY OPERATED TELEPHONE CALL TRANSMITTER Filed Nov. 16, 1944 4 Shets-Sheet 3 Has ' INVENTOR v R F MAL/1M A rmmety Feb. 12, 1946. R. F. MALLINA KEY OPERATED TELEPHONE CALL TRANSMITTER Filed Nov. 16, 1944 4 Sheets-Sheet 4 FIG. 6

INVENTOR R E MALL/NA A HO N l atented Feb. 12, 194 6- KEY OPERATED TELEPHONE CALL TRANSMITTER Rudolph F. Mallina, Hastings on Hudson, N. Y.,

assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a, corporation of- New York Application November Claims.

. This invention'relates to telephone call transmitter devices of the key operated type.

16,1944, Serial No. 563,673

The object of this invention is-to provide a call transmitter oi the type above referred to which will be simple in construction, cheap to manufac ture and convenient in operation. 7

In accordance with this invention a call transmitter is provided in which the non-uniform operation of digit numbered key members against the tension of respective retractile springs is effective to impart different angular movements to a common pivoted plate as determined by the engagement of the key members with respective stops formed in a second plate secured to and extending. perpendicularly from a base mounting the transmitter mechanism.

Means pivoted on the stop plate and movable under control of the pivoted plate as effected by the operation of any one of the keys serves to lock the other keys in the non-operated position while means carried by the common pivoted plate cooperates with means carried by each of'the keys for locking the depressed key to the pivoted plate for actuating a pulsing mech'amsm by the combined tension of a motor spring actingon the pivoted plate and the tension of the retractile spring for the depressed key both under control of a speed governor mechanism.

A plurality of means in the form of finger stops carried by the casing for the transmitter mechanism serve to assist the operator in the depression of the keys to distances corresponding to the valued the digits of these keys in addition to their respective stops in the stop plate 50 as to decrease the liability of transmitting wrong trains of pulses and'the consequent establishing of wrong telephone connections.

Other novel feature and advantages of the invention' will appear from the following description and by the claims appended thereto, reference being had to the accompanying drawings in which: I

Fig. 1 is an elevation view shown in perspective, 31c keys beingshown in the non-operatedvposition;

.bars used for holding tudinal section, the keys being'shown in the nonoperated position;

Fig. 5 is a plan view shown with a number of keys in horizontal section .and the base. with portions broken away;

Fig. 6 is a rear elevation view shown with the base and the casing in transverse vertical see- .Fig. 7 is a partial the key members in spaced relation to each other on their supporting shaft; and

Fig. 8 is a partial ,plan view, enlarged, of the pulsing and governor mechanism.

' In the call transmitter of this invention, a base III is provided for securing as by a number of screws I8 a plate PL formed with upright extendportions I land I2 serving for supporting the ends of a shaft I3 and on this shaft is pivoted a set of key members KI, K2, K3, K4, K5, K6, K1, K8,. K9 and KID formed with projections at their free ends extending, as shown in Figs. 2, 3, 4 and 5, into an opening OP in an upright ing bearing held against the stop bar I6 .thus formed at the. top end of this plate by the tension of respective retractile springs I4 best seen in Figs. 2, 3 and while stops a dl, d2, d3, d4, d5, d6, d1, d8, d9 and. dIII formed in the opening 0? of plate PL as shown in Fig. 6 to serve for limiting the movement of the keys KI, K2, K3, etc., to angular dis-' Y tances corresponding to the digit values of the key numbers KI, K2, K3, etc., in addition to the finger stops STI, ST2, 8T3, ST4, 8T5, STB, ST'I, ST8, STS and STIO secured in any convenient manner to a casing CA serving in cooperation with the base III to form a housing for the call transmitter mechanism.

On shaft I3 is pivotally mounted a pair of arms I9 and 20 to which are secured as by a plurality oi? rivets 22 the ridge or flange portions PI and P2 of a plate 2|, and to the ridge portion PI of plate 2| asshown in Figs. 4, 5 and 8 is secured by screws 23 agear sector 24 for movement with Fig. 2 is a left side elevation view shown with the base and the casing for housing the transmitter mechanism partly in vertical longitudinal section:

Fig. 3 is a view similar to Fig. 2 but showing one of the keys and the pulsing mechanism in the. operated position as effected-by the manual op the plate 2I, this plate being limited in its upward or non-operated position by 8, lug 42 best seen in Figs. 5, 6 and 8 extending laterally from an upward extending portion 4| formed with the plate PL.

The gear sector 24 engages with a pinion 25 on the hub of which is secured a pulsing cam 26. The hub of pinion 25 is mounted for free rotation on a shaft 21 and on one end of this shaft is keyed a gear 28 operatlvely connected to pinion 25 by a one-way effective clutch in the form of front view showing notched of plate PL and normally a ribbon-shaped spring SS coiled on the hub of pinion 25 and on the enlarged portion EP of shaft 21 as shown in Figs. 5, 6 and 8. The gear 26 engages with a gear 29 mounted on a shaft 36 for movement as a unit with a gear 3|, this gear in turn engages with a pinion 32 formed on ashaft 32Y to which is secured an escapement wheel 33, the teeth of which, are engaged by a pair of pins 35 laterally extending from a so-called balance wheel 36 keyed on a shaft 31.

Shafts 21, 30, 32Y and 31 are supported at one of their ends by a plate 38 supported by a pair of spacer members 39 extending laterally from the upright portions i2 and 4| of the mounting plate PL, the upright portion 4| serving to support the opposite end of shaft 21, while the upright portion |2 supports the opposite ends of shafts 31, 32Y and 30.

To the free end portions of-ridges Pi and P2 of pivoted plate 2| are secured as by riveting a pair of similarly shaped arms 45 shown in Figs. 2, 3, 4 and 5, serving for pivotally mounting a spring pressed pawl-shaped bar 46 disposed for engagement with the ratchet tooth 41 f the depressed key in-a manner and for a purpose which will be hereinafter described in detail.

The pawl bar 46 is normally held out of engagement from the teeth 41 of key K|, K2, K3, etc., by the engagement of an arm 46 carried by this pawl bar with a lug 43 formed with the upright projection H of the mounting plat PL, this plate and the gear sector 24 carried thereby together with the pawl bar 46 pivoted on the arms PI and P2 of the plate being normally held in I non-operated position as shown in Figs. 2 and 4 by a motor spring 50 having one end as shown in Figs. 2, 3, 4 and hooked to the lower end of the upright extending portion l1 and its opposite end to a downwardly extending arm 6| formed integrally with the arm i9 secured to ridge P2 of plate 2|. The key members Kl, K2, K3, etc., are provided with downwardly extending lug elements Ll, L2, L3, L4, L5, L6, L1, L6, L9 and Lin, best seen in Fig. '7 engaging respective notches in an upturned edge nb of plate PL for holding these keys in spaced relation to each other on the shaft l3 in addition to the engagement of these keys in the notches of an angle bar nbl best seen in Figs. 2, 5, 7 and 8 pivoted on lugs formed with the arms l9 and 26 to which the plate 2| is secured for pivotal movement on the shaft l3.

According to this construction the operation of any one of the key members KI, K2, K3, etc., is

effective to actuate the pivoted plate 2| through the engagement of a shoulder portion SP formed with each of the keys as shown in Figs. 2, 3 and 4 with the upper disposed edge of an upturn portion 5| formed at the front end of the pivoted plate 2|, the pivotal movement of plate 2| in turn causing the pivotal movement of the pawl bar 48 engaging the tooth thereby locking the latter to the plate 2|.

The operation of plate 2| and gear sector 24 carried thereby is effective to tension the motor spring 50 and to rotate the pulsing cam 26 which in turn actuates a pivoted pawl-like member 63 impart a corresponding angular movement to the 60 under the tension of its retractile spring 52 for 41 of the operated key and and an insulating stud 54 carried thereby in a direction away fromthe operable spring 64 of a pulsing contact shown in Figs. 2, 3 and 8' and, therefore, ineffective to open such a contact while the one-way clutch spring SS is ineflective to actuate the gear 'drive for the escapement wheel 33. a a

The pawl-like'member 53 is mounted on a shaft pawl 53 being limited in its movement away from the pulsing cam 26 by a the arm 53Y of pawl 53. A second plate 65, best seen in Figs. 2 and 3 pivoted on shaft I3 is formed at its free end with a vertically extending portion 68 extending transverse of the key members Ki, K2, K3, etc., and having grooves as '66, see Fig. 6, of difi'erent depth spring SPR engaged by engaged by their respective keys for operation by the movement of any one of these keys but a small distance from the full operated position of the latter for engaging 8. lug 61 carried by the plate 65 with a so-called breakdown spring 59 of concave-convex cross-section, the function of which being to offer a maximum resistance to the key being depressed which resistance diminishes rapidly so as to induce the full movement of the operated key by an operator and therefore the full movement 'of the gear sector 24 under control of that key.

A second pawl bar 60, as shown in Figs. 2, 3, 4 and 5, is pivoted on lugs 6| and 62 formed with the upright extending portion l1 of the mounting plate PL. This pawl bar is formed with an arm 63 held in operative relation extending from the plate 2| under the tension of a retractile spring '64, the function of pawl bar 66 being to move from the position shown in'Figs'. 2 and 4 to the position shown in Fig. 3 in engageable relation with the ratchet teeth. 66 formed at the free end of the keys Kl, K2, K6, etc., following the operation of any one of these keys for locking the non-operated keys in that position during theoperation of the pulsing mechanism as will be hereinafter described in detail. 1

In a typical operation Ofthe call transmitter 01' this invention the operation 0! any one of the key members, as key K6 for example, from the position shown in Fig. 2 to the position shown in Fig. 3 against its respective stop d6, is eflective to pivoted plate 2| through the engagement of this key with the edge of the upturned ridge or bar 6| formed with this plate. The movement of key K6 prior to reaching its step 116 formed in the upright extension H of mounting plate PL engages the upright portion 66 of pivoted plate 66 in its respective groove 66 for actuating this plate and thereby causing the lug 61 carried thereby to flex the spring 56, the function of which, as above described, is to induce the movement ofthe operated key to full depressed position. The pivotal downward movement of plate 2| and the pawl bar 46 pivoted thereon causes the movement of this pawl bar from the position shown in Fig. 2 to the position shown in Fig. 3 due to the disengagement of its arm 46 from lug 49 of upright extension i1, thus locking the operated key K6as in this example to the, plate 2| and to the gear sector 24 secured to this plate.

The operation of pivoted plate 2| as effected by the operation of the depressed key is effective to tension the motor spring 56 and to cause the pawl bar 66 to move under the tension of its retractile spring 64 from the position shown in with a lug 20 i the pivoted plate 2| responding to ated key member upon movement of the latter' the ofi-normal contacts Cl and C2 to perform switching operations well known in the automatic telephone art but which forms no part of the present invention.

The return of the operated key and that of locked to that key and therefore-the return movement of gear sector 24 and pulsing cam 36 is efiected by the tension of mo tor spring 50 and that oi'the retractile spring of the depressed key under control of the escapement-wheel 3-3 andbalance wheel 36 now operatively connected to pinion 25 by the spring clutch SS, the reverse rotary movement of cam 26being effective to actuate the pawl-like member 53 in a direction for engaging the spring 64 and thereby opening this contact a number of times cor.-

the digit number printed on the operated key, that is, six pulses when the plate 2| and gear sector 24 carried thereby engages the stop lug 42 formed with upright portion 4|.

Upon the return of the pivoted plate 2| to normal position, the arm 48 or pawl bar 46 reengages the lug 49 carried by upright for unlocking the key K6 from the plate 2| while the arm 20 of pla e 2| engages the arm 83 of pawl bar 60 for ret rning it to the position shown in Fig. 2 a small angular distance prior to the stopping of the movement-of plate 2| by the stop 42, and the transmitter is now ready for the operation of a succeeding key.

What is claimed is:

1.- In a call transmitter, a set of digit numbered key members, a plate actuated by each of said key members, means operable upon the movement of said plate for locking the latter to the operthe pawl-like member 53 I rrom normal, a spring flexed by the operation or the other of saidplates for inducing the manual movement of the operated key to full operatedposition, a gear sector carried by the firstmentioned plate, a motor spring tensioned by the movement of said plate for returning the latter to normal position, a pulsing mechanism actuated by said gear sector toward said normal position, and an escapement mechanism geared' to said sector for controlling the speed of said pulsing mechanism.

3.. In a call transmitter, a set of digit key members, a pulsing mechanism, stop elements for limiting the movement of said key members, a pivoted plate actuated by each of said key members, a gear sector carried by said plate for actuating said pulsing mechanism, and means operable upon the movement of said plate for preventing the operation or the other of said key members.

4. In a call transmitter, a mounting plate having bearing portions, a shaft journaled in said bearing portions, a set of digit numbered key members pivotally mounted on said shaft, said plate having an upright extending bent portion disposed transverse of said key members, means in said plate for defining the normal non-operated position of said key members, retractile springs for in said position, other means for limiting 'the movement of said key members to distances corresponding tothe digit values represented by said key members, a pulsing mechanism, and means actuated by said key members for actuating said pulsing mechanism for transmitting series of pulses proportional to the digit value of said key members. Y

5. In a call transmitter, a mounting plate, support elements carried by said mounting plate, a

shaft journaled in said support elements, a set of key members pivoted on said shaft, a ridge ated key, a motor spring tensioned by the move- 7 ment of said plate, a pulsing mechanism actuated upon the return'movement or said plate and the depressed key to normal, and a governor mechanism for controlling the return movement of said plate and said key. 1

2. In a call transmitter, a set of manually operable digit'numbered key members, stop elements for limiting the movement of said key members todistances proportional to the digit value of each'ot vsaid key members, a pair of plates actuated by. each of said key members, means common to each oi said key members operable for locking one .01 said plates to the operformed with said plate having means for holding said key members in spaced relation to each other on said shaft, a plate pivoted on said shaft having bearing portions, .a bar pivoted on said ,bearing portionstransverse or said'key members and adjacent said shaft, means carried by said bar for holding said keys in spaced relation to each other at points opposite said ridge, stop means for controlling the movement of said key members to distances for variably operating said pivoted plate, a gear sector carried by the last-mentioned plate for actuating said pulsing mechanism upon the operation of any one of said key members and a speed governor for controlling the operation of said pulsing mechanism. 7

RUDOLPH F,-MA1LINA..

yieldably holding saidkey members 

